Thermostat and tip-over switch



1965 c. s. MERTLER 3,201,548

THERMOSTAT AND TIP-OVER SWITCH Filed April 3, 1961 2 Sheets-Sheet 2 Fig. 6

INVENTOR.

CHARLES S. MERTLER BY ATTOR EYS' United States Patent T 3,20%,5'48 THERMQSTAT AND TIP- WEE WITCH Cherries Mertier, Mansfieid, Ghio, assignor to Stevens Manufacturing Company, Inc, a corporation of line Filed Apr. 3, I961, Ser. No. 169,384 Claims. (Cl. Mill-I38) pliances intended to be used in households have incorporated a tip-over switch wherein a plunger was mounted in the base of the appliance. This plunger was spring urged outwardly and downwardly and when the appliance was resting on the floor, the plunger was urged upwardly by the weight of the appliance against the spring force to close auxiliary switch contacts. The switch contacts would be wired in series with the normalcontrol contacts of the appliance. Should the appliance be tipped over, then the spring urged plunger would be urged outwardly by the spring to open the auxiliary contacts and, thus, render the appliance safe by de-energizing it. In electrically heated devices, this prevented the appliance catching fire to rugs or other inflammable material on the floor.

The present invention contemplates an improvement on the prior constructions by utilizing only a single set of contacts for both the control function and the tip-over function as controlled by gravity. To this end a pendulum actuates a cam and movement of the pendulum actuates the cam to, in turn, actuate the single set of control contacts. This may be in the form of separating the contacts by a camming action to de-energize the appliance in which the thermostat may be mounted.

Accordingly, an object of the invention is to provide a combined thermostat and gravity actuated switch with only a single set of contacts.

Another object of the invention is to provide a cam actuated by movement of a pendulum to separate a pair of contacts regardless of the adjustment position of the contacts.

Another object of the invention is to provide a pendulum actuated cam means to relatively separate first and second contacts with the first contact'being adjustable in response to temperature changes and the second contact being manually adjustable to control the temperature of operation of the thermostat.

Still another object of the invention is to provide a combined thermostat and tip-over switch which has Sim,- plified wiring connections and fewer operating parts for greater ease of assembly and greater reliability. Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a sectional elevational view of an electrical appliance such as a combined heater and fan incorporating a thermostat and tip-over switch embodying the invention;

FIGURE 2 is an enlarged side view of the thermostat on line 2-2 of FIGURE 1;

FIGURE 3 is a front view of the thermostat shown in FIGURE 2;

FIGURE 4 is a modified form of thermostat;

Patented Aug. 1?, W655 FIGURE 5 is another modification;

FIGURE 6 is still another modification;

FIGURE 7 is a top view of the appliance of FIGURE 1, showing a modification of mounting the thermostat, and;

FIGURE 8 is a typical wiring diagram.

The FIGURES 1, 2 and 3 show a combined thermostat and tip-over switch 11. This combined switch includes a base 12 which mounts a stack 13. First and second resilient contact blades or contact members 14 and 15 have one end fixedly carried in the stack 13. Terminals 1d and 17 are also fixed in the stack in electrical connection with the contact blades 14 and 15, respectively. Insulators such as the insulating washer 18 are provided in the stack 13 to mutually insulate the contact blades. First and second contacts 21 and 22 are carried on the first and second contact blades 14 and 15, respectively, for mutual cooperation. Bimetallic means shown as a bimetallic blade 23 is carried in the stack 13 to provide actuation of the contacts in response to temperature changes. The outboard end of the bimetallic blade 23 carries in insulator tip 24 passing through an aperture 25 in the second contact blade 15.

The base 12 may be mounted to an appliance 26 as shown in FIGURE 1 in any suitable manner. The base 12 carries an externally threaded stud 28 passing through an aperture 29 in the top cover of the appliance 26. A nut 3t) engages the stud 28 to mount the thermostat II to the appliance 26. The stud 28 may be internally threaded as a threaded nut to receive a threaded adjusting screw 32. An insulator tip 33 moved by the adjusting screw 32 passes through an aperture 34 in the first contact blade I4 and bears against the second contact blade 15. A calibrated knob 35 may be attached to the upper end of the adjusting screw 32 to provide calibrated adjustment of the temperature of actuation of the contacts 21 and 22.

A pendulum 38 has a mounting end 39. A weight as is provided on the distal end of the pendulum. A pivot axle 41 is provided longitudinally and fixed to the outboard end of the second contact blade 15. A hole is provided in the pendulum 38 at the mounting end and is pivotally received on the pivot axle 41 so that the pendulum is pivotally mounted on this second contact blade 15. Cam means 42 is provided to be actuated in accordance with movement of the pendulum and is formed as a part of the mounting end 39. This cam means has first and second cam lobes 43 and 44 and an intermediate cam fiat or cam null 45. The cam means 42 is adapted to cooperate with the first contact blade 14 and specifically, the cam lobes 43 and A4 are capable of actuating the contacts by separating them.

The pendulum 33 may be made of insulating material or at least the cam means 42 may be made of insulating material in order to provide mutual insulation between the contact blades 14 and 15.

FIGURE 8 shows a typical wiring diagram wherein the appliance 26 includes an electrical heater 48 and a fan 49. The heater and fan are connected in parallel through the control switch contacts 21 and 22 to a voltage source 559. The thermostat and tip-over switch 11 may be mounted in a convenient location such as at the top panel of the appliance 26 and the normal attitude for mounting is with the axis 51 of the adjusting screw 32 in a vertical position. Should the appliance 26 be accidentally knocked over onto its rear panel 52, the appliance '26 and, of course, the thermostat 11 would be turned through an arc approximately The pendulum 38 would, accordingly, take the position 33A relative to the thermostat 11 as illustrated in FIGURE 3. In this position, the cam lobe 43 would cooperate with the first contact blade 14 to actuate it away from the second contact blade 15. This will separate the contacts 21 and 22 a distance sutficient so that they cannot be reclosed despite any adjustment position of the adjustment screw 32 and despite any temperature responsive position of the bimetal 23. Thus, this thermostat and tip-over switch 11 is a gravity actuated device to control the contacts 21 and 22 which. are the same contacts as are controlled in accordance with temperature by the bimetal 23 and in accordance with the manually adjusted pre-set temperature by the knob 35. In the position of the thermostat as shown in full lines in FIGURE 3, it will be noted that the cam fiat 45 is that which is in cooperation with the first contact blade 14 and, accordingly, the contacts 21 and 22 are notv actuated by the cam means 42.

If the appliance 26 should fall on its front grill 53, then the pendulum would swing as urged by gravity to attempt to again establish a vertical position. As, shown in FIGURE 1; it is permissible that the thermostat ll be so mounted that apart of the'appliance Z6, namely the tan shroud 54, interferes with the movement of the pendulum 38. Nevertheless, the pendulum will move into; a position 383 as shown in FIGURE 3. This establishes the second cam lobe 44 as actuating the first contact blade M to separate the contacts 21 and 22'.

FIGURE 4 shows a modification'ot'a' thermostat and tip-over switch 51 similar to the thermostat 11 except that a pivot axle 62, may be provided on the second contact blade 15 which is transverse to the lengthwise dimension of this contact blade. pendulum 63 which has first and second cam lobes 64 and d5 and an intermediate cam null 66. In the normal position of mounting shown in FIGURE 4, the cam null 66 cooperates with the first contact blade 14- and, hence, the contacts 21. and 22 are not separated. Tipping of the thermostat 61 in either direction in a plane normal to the pivot axle 62' will cause separation of the contacts 21 and 22 by either the cam lobe 64 or the cam lobe 65. The thermostat 61- rriay be mounted in anappliance similar to the mounting of the thermostat 11 in; appliance 26.

Preferably, it would be mounted at right angles to the mounting of the thermostat ll so as to give protection for the tipping of the appliance 26 on it's rear panel or front grill, rather than merely on the two sides of the appliance 26.

FIGURE 5 shows a further modification of a combinedthermostat and tip-over switch 71; This'ithermostat is designed for mounting in the manner shown wherein the axis 72 of the stack ot'the thermostat 71 is horizontal. This thermostat 71 has a transverse pivot axle 73 on the second contact blade 15 which journals a pendulum 74; Again, this pendulum has first and second cam lobes 75 and 7e and an intermediate earn null 77 to'cooperate with the first contact blade 14. Tilting of thisthermostat 71 in either direction in a plane normal to the pivot axle 73' will provide separation of the contacts 2-1 and 22 by the cam lobes '75 or 76. 7

FIGURE 6 shows still another modified form of thermostat and tip-over switch 81 again similar to the thermostat 11 except for the mounting of the pendulum 82. In this case the lower contact blade 83 has a cup recess 84 to receive a hemisphere 85 fixed to the pendulum 82. The hemisphere 85 may be of insulating material or have an upper insulating surface to maintain insulated the first contact blade 14 and second contact blade 83. The upper surface of the hemisphere 85 may be con- This pivot axle 62 journals a ingly, with the thermostat mounted in an appliance such as the appliance 26, this tip-over switch will be effective to de-energizc the circuit no matter whether the appliance is tipped on its front or rear face or on either side face.

FIGURE 7 is a partial view showing an alternative mounting attitude for the thermostat 11 in the appliance 26. This FIGURE 7 shows that the lengthwise axis 88 of the base 12 may be established at an angle of approximately 45 relative to the front grill 53 of the appliance 26. With this manner of mounting, the thermostat and tip-over switch 11 is eilective-to de-energize the circuit for all four directions of tipping over of the appliance 25. This is because therev is a component of gravitational force which will actuate the pendulum 3% regardless of which of the four directions the appliance Z6 is tipped. Similar mounting attitudes may be established for the thermostats of FIGURES 4'and 5 in order to-make them universal in direction of actuation.

Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details'of construction and the combination and arrangement of parts may be resorted to Without departing from the spirit and the scope of the invention as hereinafter claimed.

- What is claimed is:

1. A combined thermostat and tip-over switch, comprising in combination, a hase'first and second resilient contact members having one portion thereof carried relative to said base, first and second contacts carried on said first and second contact members, respectively, for

- mutual cooperation, temperature responsive means carried relative to saidbase to relatively vary the position of said first and second contacts, adjustment means, carried relative to'said base and cooperating to relatively vary the temperature of actuation of said contacts between first and second conditions, a weighted pendulum having a mounting end, a pivot axle mounting said mounting end relative to one of said contact members, cam meansconnected to be actuated in accordance with movement of said pendulum to directly act between said contact members, a cam lobe and a cam null on said cam means, said pendulum being acted upon by gravity to attempt to hang in a vertical positionand said thermostat normally being mountable in an attitude wherein said pendulum vertical one of said cam null and cam lobe cooperates withsaid contacts to establish said contacts in said first condition, and tipping of said thermostat in a first direction establishing the other of said cam null and cam lobe in cooperation with said contacts to establish'said contacts in said second condition.

2. A combined thermostat and tip-over switch for use in an electrical appliance, comprising in combination, a

base adapted to be mounted to any said appliance, first and second resilient contact blades having one end fixedly carried relative to said base, first and second contacts respectively carried on; said first and second contact blades 'for mutual cooperation, bimetallic means carried on: said base to vary the position of said first contact relative to said second contact, screw means having a threaded connection relative to said base and cooperating with said second contact blade to vary the position of said second contact relative to said first contact, a weighted pendulum having a mounting end, cam means fixed relative tov said mounting end of said pendulum to cooperate ,With one of said contact blades, first and second cam lobes and an intermediate cam null and said cam means, said pendulum being acted upon by gravity to attempt to hang in a vertical position and said thermostat normally being mounted in an attitude wherein with said pendulum vertical said cam null cooperates with said'one of said contact blades to be ineffective in separ rating said first and second contacts, whereby tipping of said thermostat in either of first and second opposite directions establishes coaction of said first and second cam lobes, respectively, with said one of said contact blades to relatively move said first and second contacts out of mutual engagement despite the position of adjustment of said second contact blade.

3. A combined thermostat and tip-over switch for use in an eletrical appliance, comprising in combination, a base adapted to be mounted to any said appliance, first and second resilient contact blades having one end fixedly carried relative to said base, first and second contacts respectively carried on said first and second contact blades for mutual cooperation, bimetallic means carried on said base to vary the position of said first contact relative to said second contact, screw means having a threaded connection to said base and cooperating with said second contact blade to vary the position of said second contact relative to said first contact, a weighted pendulum having a mounting end, a pivot axle pivotally mounting said mounting end of said pendulum on the outboard end of one of said contact blades, cam means fixed relative to said mounting end of said pendulum to cooperate with the other of said contact blades, first and second cam lobes and an intermediate cam null on said cam means, insulating means on one of said cam means and contact blades to mutually insulate said contact blades, said pendulum being acted upon by gravity to attempt to hang in a vertical position and said thermostat normally being mounted in an attitude wherein with said pendulum vertical said cam null cooperates with said other of said contact blades to be inefi'ective in separating said first and second contacts, whereby said first and second contacts are relatively moved out of mutual engagement despite the position of adjustment of said second contact blade upon tipping of said thermostat in either of first and second opposite directions by the coaction of said first and second cam lobes, respectively, with said other of said contact blades.

4. A combined creep action thermostat and tip-over switch for mounting in an electrically heated household appliance, comprising in combination, a base, a stack fixed on said base, first and second resilient contact blades each having one end fixed in said stack, first and second contacts respectively carried on said first and second contact blades for mutual cooperation, a bimetallic blade fixed in said stack to vary the position of said first contact blade relative to said second contact blade, a threaded nut carried on said base, a screw threaded in said nut and cooperating with said second contact blade to vary the position of said second contact relative to said first contact, a pivot axle carried lengthwise on the outboard end of said second blade, an insulated pendulum pivotally carried on said axle, a weight on the distal end of said pendulum, and first and second cam surfaces on said insulated pendulum laterally disposed relative to said pivot axle and relative to the length of said pendulum to respectively cooperate with said first contact blade to move said first contact out of engagement with said second contact upon tip-over of the heating appliance and thermostat in either of first and second opposite directions, whereby said contacts are moved out of mutual engagement despite the position of adjustment of said second contact blade and despite the position of said himetallic blade.

5. A combined creep action thermostat and tip-over switch for mounting in an electrically heated household appliance, comprising in combination, a base, a stack fixed on said base, first and second resilient contact blades each having one end fixed in said stack, first and second contacts respectively carried on said first and second contact blades for mutual cooperation, a bimetallic blade fixed in said stack to vary the position of said first contact blade relative to said second contact blade, a threaded nut carried on said base, a screw threaded in said nut and cooperating with said second contact blade to vary the position of said second contact relative to said first contact, a pivot axle carried transversely on the outboard end of said second blade, an insulated pendulum pivotally carried on said axle, a weight on the distal end of said pendulum, and first and second cam surfaces on said insulated pendulum laterally disposed relative to said pivot axle and the relative to the length of said pendulum to respectively cooperate with said first contact blade to move said first contact out of engagement with said second contact upon tip-over of the heating appliance and thermostat in either of first and second opposite directions, whereby said contacts are moved out of mutual engagement despite the position of adjustment of said second contact blade and despite the position of said bimetallic blade.

References Cited by the Examiner UNITED STATES PATENTS Re 20,570 12/37 Bushway 99-329 1,665,014 4/28 Beckworth 200-139 1,797,886 3/31 Thomas 200-138 2,008,484 7/ 35 Belcher 219-251 2,074,744 3/37 Faucher 107-64 2,166,498 7/39 Lacey 290-38 2,274,390 2/42 Weeks 219-512 2,431,186 11/47 McCullough 219-252 2,768,263 10/56 Callihan 200-138 2,830,166 4/58 Loomis 219-441 2,833,903 5/58 Waddell 219-257 2,847,553 8/58 Smith 200-138 2,897,321 7/59 Patti 200-138 2,912,535 11/59 Sullivan ZOO-61.48

ROBERT K. SCHAEFER, Acting Primary Examiner.

MAX L. LEVY, E. JAMES SAX, BERNARD A. GIL- HEANY, Examiners. 

1. A COMBINED THERMOSTAT AND TIP-OVER SWITCH, COMPRISING IN COMBINATION, A BASE FIRST AND SECOND RESILIENT CONTACT MEMBERS HAVING ONE PORTION THEREOF CARRIED RELATIVE TO SAID BASE, FIRST AND SECOND CONTACTS CARRIED ON SAID FIRST AND SECOND CONTACT MEMBERS, RESPECTIVELY, FOR MUTUAL COOPERATION, TEMPERATURE RESPONSIVE MEANS CARRIED RELATIVE TO SAID BASE TO RELATIVELY VARY THE POSITION OF SAID FIRST AND SECOND CONTACTS, ADJUSTMENT MEANS CARRIED RELATIVE TO SAID BASE AND COOPERATING TO RELATIVELY VARY THE TEMPEATURE OF ACTUATION OF SAID CONTACTS, BETWEEN FIRST AND SECOND CONDITIONS, A WEIGHTED PENDULUM HAVING A MOUNTING END, A PIVOT AXLE MOUNTING SAID MOUNTING END RELATIVE TO ONE OF SAID CONTACT MEMBERS, CAM MEANS CONNECTED TO BE ACTUATED IN ACCORDANCE WITH MOVEMENT OF SAID PENDULUM TO DIRECTLY ACT BETWEEN SAID CONTACT MEMBERS, A CAM LOBE AND A CAM NULL ON SAID CAM MEANS, SAID PENDULUM BEING ACTED UPON BY GRAVITY TO ATTEMPT TO HANG IN A VERTICAL POSITION AND SAID THERMOSTAT NORMALLY BEING MOUNTABLE IN AN ATTITUDE WHEREIN SAID PENDULUM VERTICAL ONE OF SAID CAM NULL AND CAM LOBE COOPERATES WITH SAID CONTACTS TO ESTABLISH SAID CONTACTS IN SAID FIRST CONDITION, AND TIPPING OF SAID THERMOSTAT IN A FIRST DIRECTION ESTABLISHING THE OTHER OF SAID CAM NULL AND CAM LOBE IN COOPERATION WITH SAID CONTACTS TO ESTABLISH SAID CONTACTS IN SAID SECOND CONDITION. 